To determine how Trypansoma brucei acquires the sugars which it uses in the synthesis of variable antigen surface coat glycoprotein, blood stream forms of this parasite will be incubated in vitro to label the monosaccharide subunits of surface coat glycoproteins. Labeled glycoproteins will be isolated and the sugar subunits tested for radioactivity. Guided by the labeling results, cell free homogenates of T.b. brucei will be assayed for enzymes likely to be used for the interconversions observed. The enzymes which are detected will be further isolated and characterized. This research may reveal potential ways to block surface coat glycoprotein synthesis and yield a novel chemotherapy directed against brucei subgroup trypanosomiasis in man and domestic livestock.